Give reasons for the following pertaining to Hall Herault’s process.
(i) The fusion temperature of the electrolyte has to be lowered before conducting the electrolytic reduction.
(ii) The constituents of the electrolyte in addition to one part of fused alumina contains three parts of cryolite and one part of fluorspar.
(iii) A layer of powdered coke sprinkled over the electrolytic mixture, protects the carbon electrodes.
(iv) It is preferred to use a number of graphite electrodes as anode, instead of a single graphite electrode.

(i) The fusion temperature of the electrolyte has to be lowered to save energy and make the process more efficient. Lower temperatures mean less heat is needed to melt the materials, which reduces costs.

(ii) The electrolyte contains three parts of cryolite and one part of fluorspar because cryolite helps to lower the melting point of alumina, making it easier to melt. Fluorspar helps to improve the fluidity of the mixture.

(iii) A layer of powdered coke protects the carbon electrodes by preventing oxidation and reducing wear. This layer acts as a barrier, extending the life of the electrodes.

(iv) Using multiple graphite electrodes as anodes instead of one single electrode helps distribute the electrical current more evenly. This reduces the risk of overheating and improves efficiency in the electrolytic reduction process.